Question

Exercitiul 3 dau coroana sau chestie de aia

Answer 1

5(2a + 5b) = 9*(a + 3b) => 10a + 25b = 9a + 27b => a = 2b => b = a:2

7(3b + c) = 10(b + 4c) => 21b + 7c = 10b + 40c => 11 b = 33 c => b = 3c; => a:2 = 3c => a = 6c => c = a/6

(a + a/2 + a/6) / (3a - a/2 + a/6) = (10a / 6) / (16a / 6) = 10a / 16a = 5/8